1. Field of the Invention
The present invention relates to a sensing module, and more particularly to a sensing module having a plurality of chips.
2. Description of the Related Art
FIG. 1 is a schematic top view of a conventional image sensing module, and FIG. 2 is a schematic cross-sectional view along a line I-I′ of FIG. 1. Referring to FIGS. 1 and 2, the conventional image sensing module 100 includes a printed circuit board (PCB) 110, an image sensor 120, a laser diode (LD) 130, a Zener diode 140 and an encapsulation 150. The image sensor 120 is disposed on the printed circuit board 110 and is electrically connected to the printed circuit board 110. The laser diode 130 and the Zener diode 140 are electrically connected to connection terminals 160a, 160b respectively, and the connection terminals 160a, 160b are electrically connected to the printed circuit board 110 through tin solders 170a, 170b respectively.
The conventional technology employs the encapsulation 150 to package the laser diode 130, the Zener diode 140 and essential conductors (not shown), such as wires, etc. Therefore, it can not only prevent the laser diode 130, the Zener diode 140 and the conductors from being damaged or prevent contact failure between the laser diode 130, the Zener diode 140 and the conductors during the transportation of the image sensing module 100, but also modularize the laser diode 130, the Zener diode 140 and the connection terminals 160a, 160b to simplify the assembling step of the image sensing module 100. In addition, the material of the encapsulation 150 is selected from a transparent material to permit the light provided by the laser diode 130 to be transmitted out of the encapsulation 150.
However, the cost of the encapsulation 150 is high, so the production cost of the image sensing module 100 is increased. Furthermore, the encapsulation 150 will reduce the intensity of the light provided by the laser diode 130, such that the light utilization efficiency of the image sensing module 100 is reduced.